Modified Bitumen Roof Systems For Roofing In The Phoenix Area

Modified Bitumen is a single ply membrane that consists of asphalt that has plasticizers added for flexibility and a reinforcing scrim for strength. Most often installed in two or more layers and either a self-adhesive or thermo fused (torch applied). The APP modified bitumen roofing membrane is 180 mils thick, and specially designed for heat-welded applications.

This roof system is made up of a fiberglass base sheet fastened to the roof deck, and then the modified bitu-men is then heated using a torch, which activates the adhesion properties. The top surface of the membrane can be smooth or granular. This is considered a two-ply system if you are counting the fiberglass base sheet, other wise it is singular.

Phoenix Area Modified Bitumen Roof Systems

Advantages: Modified Bitumen is an excellent candidate for high traffic roof areas on commercial roofing. Has good flexibility for use in flashings or as a cap sheet in a built up roof system. Granular surface is available in multiple colors for Phoenix roof repair situations. It is very durable and ideal for flat and low-sloped roofs or areas where a roof dies into a wall or low-sloped valley area. It is easy to locate and repair leaks and inexpensive to restore.

Disadvantages: Does not perform well in ponding water situations. Torch applied systems require special training and design to reduce the risk of a fire during application. Blistering of the membrane results when the membrane is not installed at the specified tempera-ture. If the installer is in a hurry and the seams are not heated to the right temperature, delaminating at the seams may occur allowing moisture intrusion. Another issue is the proper installation of the base sheet, if not installed according to manufactures specification, the base sheet can start slipping and causing roof failure.

NOTE: A roofing contractor should have special insurance to cover fire damage.